Rockbolt and installer wand

Abstract

A rockbolt for installation in a bore in the roof of an underground excavation to support the roof and an installer wand for temporary insertion into the rockbolt to provider hardenable material to the rockbolt. The rockbolt comprises a sleeve, ports in the sleeve near the upper end, and means inside the sleeve for engaging the installer wand inserted into the sleeve. The installer wand comprises an elongated member for conducting hardenable binder, means for connecting the lower end of the elongated member to a source of hardenable binder material, and a head at the upper end of the elongated member to engage the engaging means in the rockbolt and conduct binder from the wand to the rockbolt.

We claim: 
     
       1. A rockbolt for installation in a bore in the roof of an underground excavation to support the roof, the rockbolt comprising: a sleeve insertable into the bore and having an upper and a lower end;   at least one port in the sleeve near the upper end;   means inside the sleeve near the upper end for engaging a device for supplying hardenable binder material inserted into the sleeve, said engaging means having at least one passage therein communicating with the port to allow binder material to pass from the device through the engaging means and out the port, to encase the sleeve in binder material;   means for engaging the sleeve, near the lower end, to the roof face;   means for engaging the sleeve near the upper end to the rock surrounding the bore and means for tensioning the rockbolt to compress the rock between the upper and lower ends.   
     
     
       2. The rockbolt of claim 1 wherein the means for engaging the sleeve near the upper end to the surrounding rock comprises an expandable anchor on the top of the sleeve. 
     
     
       3. A rockbolt and installer wand combination, the rockbolt being for installation in a bore in the roof of an underground excavation to support the roof, the rockbolt comprising; a sleeve insertable into the bore and having an upper and a lower end;   at least one port in the sleeve near the upper end;   means inside the sleeve near the upper end for engaging the installer wand for supplying hardenable binder material inserted into the sleeve, said engaging means having at least one passage therethrough communicating with the port to allow hardenable binder material to pass from the wand, through the engaging means, and out the port;   the installer wand being adapted for temporary insertion into the sleeve to provide hardenable binder material to the rockbolt near the upper end, the wand comprising:   an elongated member having at least one conduit therein for conducting hardenable binder material;   means for connecting the lower end of the elongated member to a source of hardenable material;   a head at the upper end of the elongated member, the head adapted to engage the engaging means in the rockbolt and having at least one passage therein communicating with the conduit and alignable with the passage in the engaging means to conduct binder from the wand to the rockbolt.   
     
     
       4. The rockbolt and installer combination of claim 3 wherein: there are a plurality of conduits in the elongated member to separately conduct the components of a hardenable binder material;   there are a plurality of passages in the engaging means in the rockbolt; and   there are a plurality of passages in the head, each passage communicating with a conduit and alignable with one of the passages in the engaging means to conduct hardenable binder material as separate components from the wand to the rockbolt.   
     
     
       5. The rockbolt and installer wand combination of claim 4 further comprising means for mixing the separate binder components in the rockbolt between the engaging means the port. 
     
     
       6. The rockbolt and installer wand combination of claim 3 wherein one of either the engaging means on the rockbolt or the head adapted to engage the engaging means has a generally cylindrical vertical stud having at least one passage extending generally axially therethrough but opening on the side of the stud and wherein the other has a generally cylindrical orifice for receiving the stud, the orifice having a passage in the side wall alignable with the passage in the stud. 
     
     
       7. The rockbolt and installer wand combination of claim 6 wherein either the stud or the orifice has sealing means above and below the passage in that member so that when the stud is inserted into the orifice an annular chamber is defined between the seals and the stud and orifice, the chamber containing and connecting the corresponding paired passages in the stud and orifice. 
     
     
       8. The rockbolt and installer wand combination of claim 4 wherein one of either the engaging means on the rockbolt or the head adapted to engage the engaging means has a generally cylindrical vertical stud having more than one passage extending generally axially therethrough but opening on the side of the stud, each passage opening being axially spaced apart from the other openings, and the other having a generally cylindrical orifice for receiving the stud, the orifice having in its side passages corresponding to the passages in the stud and axially spaced apart to be alignable with the passages in the stud. 
     
     
       9. The rockbolt and installer wand combination of claim 8 wherein either the stud or the orifice has sealing means above and below each passage so that when the stud is inserted into the orifice, annular chambers are created between the seals and the stud and orifice, each of the chambers containing and connecting a corresponding pair of passages in the stud and orifice. 
     
     
       10. The rockbolt and installer wand combination of claim 3 wherein the engaging means is in an area of reduced internal diameter inside the rockbolt near the upper end and the head on the installer wand is a generally cylindrical portion freely moveable inside the rockbolt but closely conforming to the engaging means. 
     
     
       11. The rockbolt and installer wand combination of claim 3 wherein the head of the installer wand is provided with at least one vent extending therethrough to prevent the build up of pressure above the head as the wand is inserted into the sleeve and to prevent the formation of a vacuum above the head as the wand is removed from the sleeve. 
     
     
       12. A method for supporting the roof for an underground excavation, comprising: making a bore in the roof of the excavation;   inserting into the bore a sleeve having an upper and a lower end, at least one port in the sleeve in the upper end, and means inside the sleeve near the upper end for engaging a device for supplying hardenable binder material inserted into the sleeve, said engaging means having at least one passage therein and communicating with the port to allow binder material to pass from the device through the engaging means and out the port;   temporarily inserting an installer wand into the sleeve to engage the engaging means, the installer wand comprising an elongated member having at least one conduit therein for conducting hardenable binder material, the lower end of the elongated member being connected to a source of hardenable binder material, and a head at the upper end of elongated member, the head adapted to engage the engaging means of the rockbolt and having at least one passage therein communication with the conduit and alignable with the passage in the engaging means to conduct binder from the wand to the rockbolt;   activating the source of hardenable binder material to provide binder material from the installer wand to the rockbolt.   
     
     
       13. The method of claim 12 further including the step of tensioning the sleeve to compress the rock between the upper and lower ends before extruding the binder material. 
     
     
       14. The method of claim 12 including: providing a plurality of conduits in the elongated member of the installer wand and separately conducting components of the hardenable binder material;   providing a plurality of passages in the engaging means in the rockbolt;   providing a plurality of passages in the head, each passage communicating with a conduit, aligning the passages in the engaging means, and the head, and conducting hardenable binder material as separate components from the wand to the rockbolt.   
     
     
       15. The method of claim 12 wherein the sleeve has an annular raised shoulder near its lower end, the method further comprising the step of inserting the sleeve through a face plate before inserting the sleeve into the bore. 
     
     
       16. The method of claim 12 wherein binder is extruded from the rockbolt to anchor the upper end of the rockbolt in the bore and further comprising the step of tensioning the rockbolt to compress the rock between its ends. 
     
     
       17. The method of claim 12 wherein the steps are performed with an automatic roof bolting machine.